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Extension of prioritized data analysis in the Foundation Fieldbus to three classes
Author(s) -
Lee Yong Hee,
Min Seung Hwan,
Hong Seung Ho
Publication year - 2011
Publication title -
international journal of communication systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.344
H-Index - 49
eISSN - 1099-1131
pISSN - 1074-5351
DOI - 10.1002/dac.1213
Subject(s) - computer science , security token , foundation fieldbus , foundation fieldbus h1 , token passing , data link layer , distributed computing , state (computer science) , priority ceiling protocol , service (business) , computer network , priority inheritance , fieldbus , real time computing , quality of service , algorithm , control system , telecommunications , dynamic priority scheduling , physical layer , economy , rate monotonic scheduling , electrical engineering , economics , wireless , engineering
The Foundation Fieldbus data link layer provides both a token‐passing service required for sporadic data and a scheduled service for periodic data. It has three priority levels: urgent, normal, and time‐available. Modeling the virtual token rotation time (VTRT), which is the time required to receive tokens for the transmission of one's own data, is difficult due to the interactive data delay driven by the three priority levels. Therefore, a simplified mathematical model consisting of just two priority levels has been considered. In a previous research, the VTRT probability density function was defined using the probability of a token generation; however in the present study, a simpler expression was successfully developed in a system of three priority levels by tracking the token's priority changes generated by the link active scheduler. These priority changes are tracked by using the state transition probability and the state transition diagram of a token. Therefore, the success of this new mathematical model makes this research important. Furthermore, we found the existence and the cause of a fluctuating state, both of which are useful to a system designer for setting network parameters. The validity of the analytical model was verified in a simulation experiment. Copyright © 2011 John Wiley & Sons, Ltd.